This interesting circuit was found in a 90’s American documentation. The circuit has a maximum current of 20 A and uses a transformer with the characteristics given next to the diagram.
This simple electroscope with bipolar transistors is not the most sensitive, but can detect static...
This oscillator for various frequencies was obtained from a 1980s telecom documentation. The...
This circuit is from a July 1970 Radio Electronics magazine. The sensors are metal probes. The 18 V...